The primary aims of this study are to test the effectiveness and cost-effectiveness of outpatient versus inpatient treatment for pelvic inflammatory disease (PID) in preventing involuntary infertility (i.e. lack of pregnancy despite unprotected intercourse). We propose to conduct a multicenter clinical trial of 1200 women randomized in equal numbers to an inpatient regimen consisting of parenteral cefoxitin and doxycycline for at least 48 hours, followed by doxycycline orally to complete a 14 days total course, or to an outpatient regimen consisting of a single dose of parenteral cefoxtin with probenecid, followed by doxycycline orally for 14 days. All recurrences during the follow-up period will then be treated with the same assigned regimen. Secondary aims will be to determine the impact of treatment group on a) short-term outcomes of time to clinical improvement, patient satisfaction with health care, microbiologic cure, elimination of Chlamydia trachomatis based on results of polymerase chain reaction (PCR) and immunofluorescence, and endometrial clearing by histology; and b) long-term outcomes of tubal occlusion in women with involuntary infertility, PID recurrence, ectopic pregnancy, diminished patient functionality, and frequency of health service use. Finally, the design will include a comparison of the costs associated with health care and loss of work or household management time, with the burdens of each of these long-term outcomes in women assigned to the two groups.